mpi 並行程序設計

1.添加循環和條件分支語句

#include <iostream>

#include <string.h>

#include <mpi.h>

using namespace std;

 

const int max_string = 100;

 

int main ()

{

int comm_sz=0;

int my_rank=0;

char greeting[max_string];

 

MPI_Init(NULL,NULL);

MPI_Comm_rank(MPI_COMM_WORLD,&my_rank);

MPI_Comm_size(MPI_COMM_WORLD,&comm_sz);

cout<< "Hello,I am a processor , "<<my_rank<<" of "<<comm_sz<<endl;

if(my_rank!=0){

sprintf(greeting,"Sendings from process %d of %d!",my_rank,comm_sz);

MPI_Send(greeting,strlen(greeting),MPI_CHAR,0,0,MPI_COMM_WORLD);

if(my_rank==2){

cout<<"Im "<<my_rank<<" of "<<comm_sz<<"processor i am sending "<<endl;

}

}

else{

cout<<"Im "<<my_rank<<" of "<<comm_sz<<"processor"<<endl;

cout<<"Greetings from process "<<my_rank<<" of "<<comm_sz<<"!"<<endl;

for(int i=1;i<comm_sz;i++){

MPI_Recv(greeting,max_string,MPI_CHAR,i,0,MPI_COMM_WORLD,MPI_STATUS_IGNORE);

cout<<greeting<<endl;

}

}

 

MPI_Finalize ();

return 0;

}

實驗結果